1. Field of the Invention
The present invention relates to a convertible crutch device and more particularly to a lightweight tubular crutch which may be converted from a crutch into a cane.
2. Description of the Prior Art
A search of the prior art failed to uncover any prior art references which disclose the convertible crutch of the present invention. A number of patents were uncovered which disclose convertible crutches. U.S. Pat. No. 2,960,095 to Smith, Jr. for example, discloses a convertible cane-crutch in which the crutch crossbar, which supports the user under the arm, is pivoted and folded into a vertical position aligned with the upper crutch member extending between the arm and hand support of the crutch. The crossbar is then telescoped with the upper crutch member into the lower crutch member extending between the ground and the hand support to convert the crutch into a cane. Thus, the hand support of the crutch is also used as the hand support for the cane. Furthermore, the entire weight of the crutch is carried with the cane even though portions of the crutch are unnecessary when the crutch is used as a cane.
U.S. Pat. No. 2,408,604 to Brickson discloses a convertible crutch which also uses the hand support of the crutch as the hand support for the cane when the crutch is converted to a cane by rotating or detaching the crutch arm support and upper crutch section. U.S. Pat. No. 869,128 to Autenrieth discloses a convertible crutch in which the upper crutch member is detachable for converting the crutch to a cane. Thus, in Autenrieth, as in Smith, Jr. and Brickson, the hand support of the crutch is also used as the hand support for the cane.
Also uncovered in the search was U.S. Pat. No. 2,388,778 to Wheeler, which discloses a crutch wherein the upper crutch member is rotatable about the axis of the hand support so as to lie adjacent the lower crutch member and is secured in place by a spring-loaded pin in the hand grip. It has been found that a pin in the hand grip of a crutch as in Wheeler has a tendency to wear out the pin hole under the constant application of lateral pressure thus causing the joint to become loose and flimsy. U.S. Pat. Nos. 3,133,551 and 3,157,187 to Murcott and U.S. Pat. No. 3,710,807 to Ferry disclose tubular, telescoping crutches which are not convertible into a cane. U.S. Pat. Nos. 281,245 and 2,116,941 to Degenhart and Francis, respectively, disclose spike tips for use on crutches or canes for contacting the ground in a non-slip manner.
Several of the aforementioned prior art patents disclose crutches having means for adjusting the spacing between the crutch arm support and hand support and between the hand support and the ground-engaging tip of the crutch by means of telescoping members with spring-biased locking pins (Ferry, Murcott, Smith, Jr.) or by means of screws, fixed pins or the like (Wheeler, Brickson, Autenrieth). While spring-biased pins are much more convenient and readily adjustable than screws, there is always the danger that the pins will become worn or disengaged resulting in inadvertent telescoping of the crutch and possible injury to the user. Where screws are used, of course, tools are required to adjust the position of the arm and hand supports of the crutch.